Solution: Scanning at high resolutions produces very large files: for example, whereas a 72 dpi colour (RGB) scan of an A4 page uses 1.43 MB of disk space, the same scan at 300 dpi uses 24.9 MB, at 600 dpi, it uses 99.6MB, while at 4800 dpi, it requires around 6.4 gigabytes of memory!

As a rule of thumb, a PC should have at least as much RAM as the size that will be occupied by the image to be scanned, and at least double the free disk space on the hard disk. A higher amount of free space will improve the scanner’s (and the computer’s) performance.

Note: CMYK scans are 25 per cent larger than RGB scans, while greyscale scans are a third of the size of RGB scans.